Isotope dilution--mass spectrometric quantification of specific proteins: model application with apolipoprotein A-I

An enzymatic hydrolysis isotope dilution-mass spectrometric method was developed for reference quantification of specific proteins. The analytical procedure involved measuring a reproducibly hydrolyzed peptide (serving as the primary standard) unique to a specific protein. This new mass spectrometric method was evaluated by assessing the concentration of apolipoprotein (apo) A-I in the European Community Bureau of Reference (BCR) lyophilized Certified Reference Material (CRM 393). We used the method to make 96 measurements (4 replicate analyses of 4 enzymatic digests of 6 vials of BCR-CRM 393), which gave an average total protein mass of 1.048 mg (+/- 1.0% at 99% confidence limits). The total overall analytical CV was 3.95%. The results of this evaluation of our model approach to determine the concentration of a specific protein in a purified preparation demonstrated that our new mass spectrometric method can be used to measure apolipoproteins and other specific proteins without the use of epitopic immunoassay methods.     

A 14-b 2.5 MSPS pipelined ADC with on-chip EPROM

A 14-b 2.5 MSPS, multistage pipeline, subranging analog-to-digital converter is presented. In addition to conventional laser-wafer-trim, on chip, “write once” EPROM is used to calibrate inter-stage gain errors at package sort. Integral nonlinearity errors as small as ±1.5 LSB and differential nonlinearity errors of ±0.5 LSB have been achieved. The 5.4 mm by 4.4 mm device includes a 2.5 V reference and is built on a 2 μm 10 V BiCMOS process and consumes 500 mW of power     

Dysfunctional beliefs and attitudes about sleep among older adults with and without insomnia complaints.

Examined the beliefs and attitudes about sleep among 145 older adults. Ss were either chronic insomniacs (n?=?74) or self-defined good sleepers (n?=?71). They rated their level of agreement or disagreement (visual analog scale) with 28 statements tapping various beliefs, expectations, and attributions about several sleep-related themes. The results showed that insomniacs endorsed stronger beliefs about the negative consequences of insomnia, expressed more hopelessness about the fear of losing control of their sleep, and more helplessness about its unpredictability. Findings suggest that some beliefs and attitudes about sleep may be instrumental in perpetuating insomnia. The main clinical implication is that these cognitions should be identified and targeted for alteration in the management of late-life insomnia. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The medical record: a comprehensive computer system for the family physician

BACKGROUND: Despite the early excitement regarding the possible uses of computers in medical care in the 1980s, the computer has not had much effect on routine outpatient medicine except for billing and accounting. METHODS: An emerging comprehensive ambulatory care computer system, The Medical Record (TMR), is used extensively in a large family practice, the Duke Family Medicine Center. TMR is the central system for accounting, appointments, billing, and reporting of laboratory results, radiographic findings, and medications. TMR also records problem lists and generates prompts to the clinicians for needed health maintenance, laboratory tests, and reminder letters. The most innovative function of TMR is the computerized obstetric patient record, which can be accessed from multiple sites. Cost savings compared with a manual system were found to be in excess of $7 per patient visit or approximately $500,000 per year for the Duke Family Medicine Center. RESULTS AND CONCLUSIONS: A comprehensive computer system in a large family practice is cost effective and facilitates better patient care through improved access to patient data.     

Hip fracture rates in Hong Kong and the United States, 1988 through 1989

OBJECTIVES: Prior studies have suggested that hip fracture rates are substantially lower in Asian countries than in the United States. However, comparisons have been limited by unavailability of recent data, differences in case definition, lack of data from similar time periods, and small sample sizes. This study sought to examine trends by age and sex, with separate statistics for those aged 85 or older. METHODS: Hospital discharge data were used to obtain hip fracture incidence in Hong Kong and the United States from 1988 through 1989. RESULTS: Within each population, women had higher hip fracture rates than men. Fracture rates in the United States were significantly higher for both sexes than rates in Hong Kong. For persons over the age of 80, rates of hip fracture among White US males exceeded those for Hong Kong women. Inclusion of transferred cases in hip fracture rates minimized differences between the countries. CONCLUSIONS: Despite increasing hip fracture rates in Hong Kong, those rates are still substantially lower than the rates in the United States. Identifying factors responsible for this variation may prove useful in the search for preventive strategies.     

The effect of cellular energetics on foreign protein production

Escherichia coli strain F-122 was used to determine if there are additional physiological effects, other than decreasing energetic efficiency accompanied by the excretion of the acetate, on foreign protein production. This organism was the host for expressing HIV582-beta-galactosidase fusion protein under the control of the trp promoter, with ampicillin resistance. By comparing parallel batch cultures with and without acetate addition, it was found that the presence of acetate in the media did not influence beta-galactosidase activity. In these experiments, it appears that the low protein productivity often observed during acetate formation is the result of inefficient cell metabolism, rather than acetate acting as a specific inhibitor of protein production.     

Analysis of the micropipet experiment with the anisotropic outer hair cell wall

The outer hair cell makes both passive and active contributions to basilar membrane mechanics. The outer hair cell mechanics is strongly coupled to the elastic properties of the cell lateral wall. The lateral wall experiences both in-plane deformations and bending under physiological and experimental conditions. To characterize the outer hair cell wall, the model of an orthotropic cylindrical shell is used. The elastic constants of the wall are estimated by solving a set of three equations based on the analyses of three independent experiments. The first equation is derived from a new interpretation of the micropipet experiment; the other two are obtained from the axial loading and the osmotic challenge experiments. The two Young's moduli corresponding to the longitudinal and circumferential directions and two Poisson's ratios are estimated. The longitudinal, circumferential, and mixed modes of the bending stiffness are also estimated. The sensitivity of the derived constants to the variation of the cell axial stiffness, which has been measured by several independent groups, is examined. The new estimates are also compared with results obtained by using the assumption of the wall isotropy.